This application claims priority of Korea patent Application No. 99-58232, filed on Dec. 16, 1999.
1. Field of the Invention
The present invention relates to a foot brake, and more particularly to a release device of a foot brake adapted to completely release a parked state of the foot brake just by instantly pulling a parking release knob, thereby removing inconvenience of separately checking whether the parking state is completely released and promoting a safe operation of an automobile.
2. Description of the Prior Art
Generally, a parking brake of an automobile serves to brake rear wheels for maintaining a braked state when the automobile is parked, and a parking brake according to the prior art is operated to brake an automobile by adhering a parking brake shoe at the rear wheels to a parking brake drum when an operator pulls a parking brake manipulating lever, at which time, frictional force generated therefrom brakes the automobile.
Meanwhile, besides the hand brake thus described, a foot parking brake for braking an automobile by applying pressure by foot is disclosed. A foot parking brake according to the prior art is depicted in FIGS. 1, 2 and 3, where a floor panel near a driver is mounted with an installation panel 2 on which a parking brake pedal 1 is rotatively hinged thereto, and the parking brake pedal 1 is connected at one tip end thereof to one tip end of a parking brake cable 7.
The parking brake pedal 1 is formed at one side thereof with a ratchet gear 3, and a ratchet plate 5 meshes with the ratchet gear and is rotatively supported to the installation plate 2 via a rotary axle 5a. 
Furthermore, the ratchet plate 5 is rotatively supported at the rotary axle 5a thereof by one side of a release lever 17, while the release lever 17 is connected at the other end thereof to one end of a parking release cable 9. The parking release cable 9 is mounted at the other end thereof with a parking release knob 9a for a driver to manipulate.
The ratchet plate 5 is wound with a torsion spring 11 while the torsion spring 11 is fixed at one end thereof to a bracket 2a of the installation plate 2.
Furthermore, between a predetermined area of the installation plate 2 and the parking brake pedal 1 there is formed a pedal damper 19 for softening the shock when the parking brake pedal 1 is pressed or released. The pedal 1 is connected to a return spring 13 while the ratchet plate 5 is connected to another return spring 15.
When a drive steps on the parking brake pedal 1 for parking an automobile, the pedal 1 is rotated via a hinge toward an arrow xe2x80x9cAxe2x80x9d direction in FIG. 2 (counterclockwise) whereby, the parking brake cable 7 connected to the pedal 1 is pulled to cause a rear parking brake shoe to adhere to a parking brake drum and to allow a parking brake to actuate.
At this time, the parking brake can maintain the actuated state as long as the parking brake pedal 1 keeps a counterclockwise rotating state, the role of which is taken care of by the torsion spring 11.
In other words, when the parking brake pedal 1 is rotated counterclockwise by manipulation of a driver while the ratchet gear 3 of the parking brake pedal 1 is meshed with ratchet gear of the ratchet plate 5, the torsion spring 11 wound around the ratchet plate 5 is slackened. However, when the parking brake pedal 1 is freed by the driver, the parking brake pedal 1 tends to rotate clockwise by the return spring 13, at which time, the torsion spring 11 is wound by rotation of the ratchet plate 5. When the torsion spring 11 is wound to a predetermined level, the spring 11 can no longer be wound, which causes the ratchet plate 5 to be locked and also makes the parking brake pedal 1 meshed to the ratchet plate 5 locked, whereby the parking brake pedal 1 keeps maintaining the counterclockwise rotated state.
Meanwhile, in releasing the parking brake, the driver pulls the parking release knob 9a to allow the release lever 17 to rotate via the parking release cable 9 connected to the parking release knob 9a, whereby a protruder 17b formed at an extension 17a of the release lever 17 pushes a free end 11b of the torsion spring 11 to slacken the wound torsion spring 11 to a predetermined length. By this, the ratchet plate 5 and the parking brake pedal 1 are freed from the torsion spring 11 to return to original position via respective return springs 15 and 13.
However, there is a problem in the releasing operation of the foot brake according to the prior art thus described in that torsion spring""s pushing state of free end 11b by the release lever 17 should be kept for a predetermined period of time while the parking release is actuated to smoothly turn the ratchet plate 5 and the parking brake pedal to a rotatable state, but if the driver pulls and instantly releases the parking release knob 9a, the parking brake pedal 1 cannot be completely returned to rotation due to locking operation of the torsion spring, thereby enabling an automobile to run even while the parking brake is actuated.
Particularly, there is another problem in that viscosity of oil in damper in cold weather gets reduced, making a driver pull the parking release knob for a long time.
The present invention is disclosed to solve the aforementioned problems and it is an object of the present invention to provide a foot brake release device adapted to completely release a parking actuated state of a parking brake pedal just by instantly pulling a parking release knob for releasing the parking actuated state of the parking brake pedal, thereby removing inconvenience of separately checking whether the parking actuated state is completely released and promoting a safe operation of an automobile.
In accordance with the object of the present invention, there is provided a foot brake release device, the device comprising:
a parking brake pedal equipped at one side thereof with a ratchet gear and mounted rotatively;
a ratchet plate equipped with a ratchet gear meshed to a ratchet gear and mounted rotatively;
a torsion spring mounted at the ratchet plate for the parking brake pedal to rotate at a predetermined angle for maintenance of a locked state and to restrict the ratchet plate from rotating in one direction; and
torsion spring slack keeping means for maintaining slacked state of the torsion spring when the parking brake pedal is returned for rotation, wherein the torsion spring slack keeping means further comprises:
a hinge member;
a lock lever mounted with a first bend rotatively connected to the hinge member and contactable to the ratchet plate, and a second bend extended to contact a free end of the torsion spring; and
resilient member mounted at the lock lever for resiliently supporting the lock lever.